A cathode ray tube (CRT) had been most widely used among various display devices displaying image information. However, the CRT caused many inconveniences in use due to its relatively great volume and a heavy weight compared to its display area.
Accordingly, thin flat display devices that have a slim profile and a large display area and thus can be easily used in any place have been developed and are gradually replacing CRTs. Particularly, liquid crystal display (LCD) devices have excellent display resolution compared to other flat display device and have fast response time that can be compared to that of CRTs when realizing a moving image.
FIG. 1 is a view illustrating a related art LCD device. Referring to FIG. 1, the related art LCD device includes a first substrate 10, a second substrate 20, and a liquid crystal layer 30 formed between the first substrate 10 and the second substrate 20. The LCD device includes a first polarizer 12 formed under the first substrate 10, and a second polarizer 22 formed on the second substrate 20.
An array device having thin film transistors (TFTs), and pixel electrodes 14 transmitting incident light are formed on the first substrate 10. Although not shown, the array device includes a plurality of gate lines, a plurality of data lines, pixel regions defined by the gate lines and the data lines, and the TFTs formed at intersections of the gate lines and the data lines.
A black matrix 26, a color filter 28, and a common electrode 24 are formed under the second substrate 20.
In the LCD device having such a structure, the TFT, a switching device, is disposed in each pixel. The TFT is switched when a scan signal is input through the gate line, and thus applies a signal inputted by the data line to the liquid crystal layer 30.
Since liquid crystals have molecular arrangement with directionality and polarity, the molecular arrangement is controlled when an electric field is artificially applied to liquid crystal molecules injected into a cell gap of a liquid crystal panel. Thus, an alignment direction of the liquid crystal molecules can be controlled by a signal applied to the liquid crystal layer 30. Since the control of the alignment direction of the liquid crystal layer 30 may allow transmitting or blocking of light, light passing through the liquid crystal layer 30 implements colors and images.
However, the LCD device is disadvantageous in that the color gamut is undesirably reduced by a transmittance characteristic of a color filter since color reproduction is made when white light having passed through the liquid crystal layer 30 passes through the color filter.
Also, since the liquid crystals are driven by an applied electric field, a response time of the liquid crystals is somewhat slow, which may cause afterimages when images change swiftly.
Therefore, a liquid crystal display device having a high response rate are needed to stably obtain a high quality, high resolution image. Also, a driving method of the LCD device, which is able to display a visually comfortable moving image, is also needed.